The present invention relates to laundry detergent compositions which prevent the re-deposition of soil onto fabric which has been entrained into cellulosic material derived form fabric or other source. The surprising results are obtained from the combination of a zwitterionic polyamine and an enzyme system which comprises a xyloglucanase enzyme, preferably a xyloglucanase enzyme and a mannanase enzyme.
Enzymes are now routinely comprise laundry detergent compositions. The variability of stains and soils is now effectively matched with one or more correspondingly effective enzymes. Proteinaceous stains are removed by protease enzymes while cellulase enzymes are used to obliterate and remove cellulosic material based stains and soils.
Regardless of how effective enzymes are at breaking up specific soils and providing a means for the removal of said stains from fabric, enzymes themselves can not serve to abate the re-deposition of soils back onto fabric itself. Enzymes which are effective at cutting the chemical bonds of the primary cell wall of cellulosic fabric are able to release entrapped soils for removal by surfactants. However, much of the xyloglucan comprising primary cell wall of cellulose comprising fibers is damaged due to mechanical wear either outside the laundry process or during laundering itself. The broken fiber material is finally loosened and removed during the mechanical wash, however this material can attract loosened soils and dirt, form an amorphous material which then re-deposits onto fabric.
There is a long felt need for a laundry detergent which is capable of breaking down loosened cellulosic material which entraps and re-deposits soil onto fabric. There is also a long felt need for an enzyme system which will maintain cellulosic fabric in a manner which abates the entrapping and embedding of soils which can be acted upon by other enzymes, inter alia, protease enzymes.
The present invention meets the aforementioned needs in that it has been surprisingly discovered that liquid laundry detergent compositions comprising a combination of xyloglucanase enzymes and one or more zwitterionic polyamines produces enhance soil removal properties. It has also been surprisingly discovered that a preferred enzyme system according to the present invention comprises a mixture xyloglucanase and mannanase enzymes, preferably in combination with one or more other detersive enzymes. It has also been surprisingly discovered that the formulator may selected the final pH of said compositions from about pH 7.2 to about pH 9.
The first aspect of the present invention relates to liquid laundry detergent compositions which comprise:
a) from about 0.01%, preferably from about 0.1%, more preferably from about 0.5%, most preferably form about 1% to about 10%, preferably to about 5%, more preferably to about 3%, most preferably to about 2% by weight, of a zwitterionic polyamine which comprises a polyamine backbone, said backbone comprising two or more amino units wherein at least one of said amino units is quaternized and wherein at least one amino unit is substituted by one or more moieties capable of having an anionic charge wherein further the number of amino unit substitutions which comprise said anionic moiety is less than or equal to the number of quaternized backbone amino units;
b) from about 0.00005%, preferably form about 0.0001% to about 0.005%, preferably to about 0.001% by weight, of a xyloglucanase enzyme;
c) from about 0.5% to about 50% by weight, of a surfactant system comprising:
i) from about 10% to about 99% by weight, of said surfactant system, of a nonionic surfactant;
ii) from about 1% to about 90% by weight, of said surfactant system, of an anionic surfactant;
iii) optionally, from 1% to about 50% by weight, of said surfactant system, of a detersive surfactant selected from the group consisting of cationic surfactants, zwitterionic surfactants, ampholytic surfactants, and mixtures thereof, and
d) the balance carriers and adjunct ingredients.
The present invention also relates to enzyme systems comprising:
i) from about 20% to about 99% by weight, of a said enzyme system, a xyloglucanase enzyme;
ii) from about 1% to about 80% by weight, of said enzyme system, a mannanase enzyme;
iii) optionally, from 1% to 80% by weight, of said enzyme system one or more enzymes selected from the group consisting of protease enzymes, amylase enzymes, cellulase enzymes, lipolase enzymes, lipase enzymes, peroxidase enzymes, cutinase enzymes, and mixtures thereof.
The present invention further relates to a method for treating fabric with an aqueous solution of a xyloglucanase enzyme containing liquid laundry detergent composition wherein the aqueous concentration of said xyloglucanase is from about 0.5 ppm to about 50 ppm, wherein said composition further comprises one or more zwitterionic polyamines.
These and other objects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (xc2x0C.) unless otherwise specified. All documents cited are in relevant part, incorporated herein by reference.
The present invention relates to liquid laundry detergent compositions which have enhanced soil removal benefits. The combination of a xyloglucanase enzyme with a zwitterionic polyamine dispersant provides soil removal from cellulosic fabric and improved soil anti-redeposition properties. The present invention prevents the entrapment of soils into residues which can be re-deposited onto fabric.
Without wishing to be limited by theory, cellulosic fabric comprises fibers wherein xylogluncan is a primary cell wall constituent. The primary cell wall (outer layer of fiber) is damaged due to abrasion from wear the fabric and is also damaged by the enzymes which comprise detergent compositions, inter alia, cellulases. The xyloglucan cellular material which comprises a piece of cellulosic fabric may become loosened or detached due to these circumstances and during the laundering process several pejorative consequences to fabric cleaning can result. In one case the loosened and detachable xyloglucan is lifted from the surface of fabric. This amorphous, glue-like material is usually large enough in molecular weight that is not easily solublized or dispersed, but instead, is present along the fabric surface where it can entrain loosened or removed soil. Once the amorphous xyloglucan containing material is contaminated with soil, it has a propensity to re-deposit onto the surface of fabric thereby producing an entrapped area of soil.
Alternatively, long strings of xyloglucan polymer can become semi-detached from the cellulosic fabric primary cell wall and this glue-like material in turn can entrap soils which have been removed from the fabric surface. In addition, other enzymes which are present, protease enzymes, inter alia, may produce fragments of foreign stain material which, instead of being carried away by the laundry liquor, become immediately imbedded within the amorphous xyloglucan strands.
It has now been surprisingly discovered that the presence of xyloglucanase enzyme together with a fabric surface active zwitterionic polyamine inhibits the entrapment of soils and stain material by xyloglucan cell wall fragments. During the laundry process, xyloglucanase enzymes cut the xyloglucan fragments completely free of the cellulosic primary cell wall thereby providing a virtually renewed fiber surface. In addition, the xyloglucanase enzymes react with the amorphous, glue-like material and produce a water soluble or dispersible material which is incapable of re-depositing onto fabric or incapable of entrapping soil or stain material.
It has also been surprisingly discovered that in some instances liquid laundry detergent compositions which comprise an enzyme system wherein a mannanase enzyme is formulated in combination with a xyloglucanase enzyme produce an enhanced cleaning effect.
The following is a description of the essential elements of the present invention.
Zwitterionic Polyamines
The zwitterionic polyamines of the present invention comprise from about 0.01%, preferably from about 0.1%, more preferably from about 0.5%, most preferably form about 1% to about 10%, preferably to about 5%, more preferably to about 3%, most preferably to about 2% by weight, of the final laundry detergent composition. The zwitterionic polymers of the present invention are suitable for use in liquid laundry detergent compositions, inter alia, gels, thixotropic liquids, and pourable liquids (i.e., dispersions, isotropic solutions).
It has been surprisingly discovered that the formulator, by selecting the relative degree of quaternization of the polyamine backbone, the type and relative degree of incorporation of anionic units which substitute the polyamine backbone, and the nature of the amine backbone itself, is able to form a zwitterionic polymer which can be tailored for optimal effectiveness in a compositions comprising a xyloglucanase enzyme or an enzyme system which comprises a xyloglucanase enzyme. Therefore, key to the selection of properties which affects optimization is the desired execution. Preferably, as described herein below, the zwitterionic polymers which are incorporated into xyloglucanase containing liquid laundry detergent compositions have an excess number of quaternized backbone nitrogens relative to the number of anionic units which are present.
For the purposes of the present invention the term xe2x80x9ccharge ratioxe2x80x9d, Qr, is defined herein as xe2x80x9cthe quotient derived from dividing the sum of the number of anionic units present excluding counter ions by the sum of the number of quaternary ammonium backbone unitsxe2x80x9d. The charge ratio is defined by the expression:       Q    r    =            ∑              q        anionic                    ∑              q        cationic            
wherein qanionic is an anionic unit, inter alia, xe2x80x94SO3M, as defined herein below and qcationic represents a quaternized backbone nitrogen.
Those of skill in the art will realize that the greater the number of amine units which comprise the polyamine backbones of the present invention the greater the number of potential cationic units will be contained therein. For the purposes of the present invention the term xe2x80x9cdegree of quaternizationxe2x80x9d is defined herein as xe2x80x9cthe number of backbone units which are quaternized divided by the number of backbone units which comprise the polyamine backbonexe2x80x9d. The degree of quaternization, Q(+), is defined by the expression:       Q    ⁢          (      +      )        =            ∑              quaternized        ⁢                  xe2x80x83                ⁢        backbone        ⁢                  xe2x80x83                ⁢        nitrogens                    ∑              quaternizable        ⁢                  xe2x80x83                ⁢        backbone        ⁢                  xe2x80x83                ⁢        nitrogens            
wherein a polyamine having all of the quaternizable backbone nitrogens quaternized will have a Q(+) equal to 1. For the purposes of the present invention the term xe2x80x9cquaternizable nitrogenxe2x80x9d refers to nitrogen atoms in the polyamine backbone which are capable of forming quaternary ammonium ions. This excludes nitrogens not capable of ammonium ion formation, inter alia, amides.
For the purposes of the present invention the term xe2x80x9canionic characterxe2x80x9d, xcex94Q, is defined herein as xe2x80x9cthe sum of the number of anionic units which comprise the zwitterionic polymer minus the number or quaternary ammonium backbone unitsxe2x80x9d. The greater the excess number of anionic units, the greater the anionic character of the zwitterionic polymer. It will be recognized by the formulator that some anionic units may have more than one unit which has a negative charge. For the purposes of the present invention units having more than one negatively charged moiety, xe2x80x94CH2CH(SO3M)CH2SO3M, inter alia, will have each moiety capable of having a negative charge counted toward the sum of anionic units. The anionic character is defined by the expression:
xcex94Q=xcexa3qanionicxe2x88x92qcationic
wherein qanionic and qcationic are the same as defined herein above.
As described herein below, a key aspect of the present invention is the finding that the formulator, by adjusting the parameters Qr, xcex94Q, and Q(+), will be capable of customizing a polymer to formulate liquid laundry detergent compositions having enhanced particulate soil removal benefits throughout a wide variety of settings, for example as a function of (1) the nature of the polymeric structure itself (e.g., EO level, MW, length and HLB of the amine backbone, etc.), (2) the detergent matrix (e.g., pH, type of surfactant), (3) the particular embodiment (e.g., liquids, gel, structured liquid, non-aqueous, etc.), and (4) desired benefit (e.g., clay stain removal, whiteness, dingy cleaning, etc.). Therefore, in one desired embodiment the zwitterionic polymers of the present invention may have a Qr of from about 1 to about 2, whereas another embodiment will employ zwitterionic polymers having a Qr greater than 2. Specific embodiments, as described herein below, may require a Qr significantly less than 1 or even zero.
Liquid laundry detergent compositions may comprise clay soil dispersants which adsorb on the anionic surfaces of dislodged clay particles and form a stabilized suspension of the particles and hold the particles in solution until they are removed during the rinsing process thus preventing the particles from re-depositing upon the fabric surface. An example of preferred hydrophilic dispersants which are further described herein below, is a dispersant which comprises a polyethyleneimine backbone having an average molecular weight of about 189 daltons and in which each nitrogen which comprises said backbone has the appended hydrogen atom replaced by an ethyleneoxy unit having from 15 to 18 residues on average. This preferred ethoxylated polyethyleneimine dispersant is herein after referred to as PEI 189 E15-18. This dispersant is highly effective in dispersing clay soils once the clay soils are removed from fabric.
Subtle changes to the structure of polyalkyleneimines can provide profound changes to the properties thereof. For example, a preferred hydrophobic dispersant capable of dispersing soot, grime, oils, carbonaceous material, comprises a polyethyleneimine having a backbone with an average molecular weight of about 1800 daltons and in which each nitrogen which comprises said backbone has the appended hydrogen atom replaced by an ethyleneoxy unit having from about 0.5 to about 10 residues on average, preferably an average of 7 residues, for example, PEI 1800 E7. The ability to affect profound changes in the properties of polyamines by making small changes to the structure of said polyamines is known and appreciated throughout the laundry art.
Knowing the propensity of these polyamines to exhibit activity in the aqueous laundry liquor, it is therefore surprising and highly unexpected that zwitterionic polyamines having hydrophilic backbone components would act synergistically with certain mid-chain branched surfactants to enhance the removal of clay and other hydrophilic soils directly from fabric fiber itself. Without wishing to be bound by theory it is believed the zwitterionic polyamines of the present invention interact with the mid-chain branched surfactants in a manner which makes clay and other cationic surfaces more anionic in nature. It is believed this system absorbs the modified clay particles from the fiber surface and the inherent agitation associated with the laundry process (for example, the agitation provided by an automatic washing machine) acts to break the once formed complexes loose from the fabric surface and disperse them into solution. The clay and other hydrophilic particles which are removed by the compositions of the present invention are those types of stains or particles which are not well removed by normal surfactant/dispersant systems.
Although other surfactants, inter alia, non mid-chain branched sulphonates and sulphates, nonionic surfactants, are highly desirable components of the herein described granular laundry detergent compositions, their absence or presence does not affect the ability of the zwitterionic polyamine/mid-chain branched surfactant system to enhance clay soil removal.
The zwitterionic polymers of the present invention are comprised of a polyamine backbone wherein the backbone units which connect the amino units can be modified by the formulator to achieve varying levels of product enhancement, inter alia, boosting of clay soil removal by surfactants, greater effectiveness in high soil loading usage. In addition to modification of the backbone compositions, the formulator may preferably substitute one or more of the backbone amino unit hydrogens by other units, inter alia, alkyleneoxy units having a terminal anionic moiety. In addition, the nitrogens of the backbone may be oxidized to the N-oxide. Preferably at least two of the nitrogens of the polyamine backbones are quaternized.
For the purposes of the present invention xe2x80x9ccationic unitsxe2x80x9d are defined as xe2x80x9cunits which are capable of having a positive chargexe2x80x9d. For the purposes of the zwitterionic polyamines of the present invention the cationic units are the quaternary ammonium nitrogens of the polyamine backbones. For the purposes of the present invention xe2x80x9canionic unitsxe2x80x9d are defined as xe2x80x9cunits which are capable of having a negative chargexe2x80x9d. For the purposes of the zwitterionic polyamines of the present invention the anionic units are xe2x80x9cunits which alone, or as a part of another unit, substitute for hydrogens along the polyamine backbonexe2x80x9d a non-limiting example of which is a xe2x80x94(CH2CH2O)20SO3Na which is capable of replacing a backbone hydrogen on a nitrogen or oxygen atom.
The zwitterionic polyamines of the present invention have the formula:
[Jxe2x80x94R]nxe2x80x94J
wherein the [Jxe2x80x94R] units represent the amino units which comprise the main backbone and any branching chains. Preferably the zwitterionic polyamines prior to modification, inter alia, quaternization, substitution of a backbone unit hydrogen with an alkyleneoxy unit, have backbones which comprise from 2 to about 100 amino units. The index n which describes the number of backbone units present is further described herein below.
J units are the backbone amino units, said units are selected from the group consisting of:
i) primary amino units having the formula:
(R1)2N;
ii) secondary amino units having the formula:
xe2x80x94R1N;
iii) tertiary amino units having the formula: 
iv) primary quaternary amino units having the formula: 
v) secondary quaternary amino units having the formula: 
vi) tertiary quaternary amino units having the formula: 
vii) primary N-oxide amino units having the formula: 
viii) secondary N-oxide amino units having the formula: 
ix) tertiary N-oxide amino units having the formula: 
x) and mixtures thereof.
B units which have the formula:
[Jxe2x80x94R]xe2x80x94
represent a continuation of the zwitterionic polyamine backbone by branching. The number of B units present, as well as, any further amino units which comprise the branches are reflected in the total value of the index n.
The backbone amino units of the zwitterionic polymers are connected by one or more R units, said R units are selected from the group consisting of:
i) C2-C12 linear alkylene, C3-C12 branched alkylene, or mixtures thereof; preferably C3-C6 alkylene. When two adjacent nitrogens of the polyamine backbone are N-oxides, preferably the alkylene backbone unit which separates said units are C4 units or greater.
ii) alkyleneoxyalkylene units having the formula:
xe2x80x94(R2O)w(R3)xe2x80x94
wherein R2 is selected from the group consisting of ethylene, 1,2-propylene, 1,3-propylene, 1,2-butylene, 1,4-butylene, and mixtures thereof; R3 is C2-C8 linear alkylene, C3-C8 branched alkylene, phenylene, substituted phenylene, and mixtures thereof; the index w is from 0 to about 25. R2 and R3 units may also comprise other backbone units. When comprising alkyleneoxyalkylene units R2 and R3 units are preferably mixtures of ethylene, propylene and butylene and the index w is from 1, preferably from about 2 to about 10, preferably to about 6.
iii) hydroxyalkylene units having the formula: 
wherein R4 is hydrogen, C1-C6 alkyl, xe2x80x94(CH2)u(R2O)t(CH2)uY, and mixtures thereof. When R units comprise hydroxyalkylene units, R4 is preferably hydrogen or xe2x80x94(CH2)u(R2O)t(CH2)uY wherein the index t is greater than 0, preferably from 10 to 30; the index u is from 0 to 6; and Y is preferably hydrogen or an anionic unit, more preferably xe2x80x94SO3M. The indices x, y, and z are each independently from 1 to 6, preferably the indices are each equal to 1 and R4 is hydrogen (2-hydroxypropylene unit) or (R2O)tY, or for polyhydroxy units y is preferably 2 or 3. A preferred hydroxyalkylene unit is the 2-hydroxypropylene unit which can, for example, be suitably formed from glycidyl ether forming reagents, inter alia, epihalohydrin.
iv) hydroxyalkylene/oxyalkylene units having the formula: 
wherein R2, R4, and the indices w, x, y, and z are the same as defined herein above. X is oxygen or the amino unit xe2x80x94NR4xe2x80x94, the index r is 0 or 1. The indices j and k are each independently from 1 to 20. When alkyleneoxy units are absent the index w is 0. Non-limiting examples of preferred hydroxyalkylene/oxyalkylene units have the formula: 
v) carboxyalkyleneoxy units having the formula: 
wherein R2, R3, X, r, and w are the same as defined herein above. Non-limiting examples of preferred carboxyalkyleneoxy units include: 
vi) backbone branching units having the formula: 
wherein R4 is hydrogen C1-C6 alkyl, xe2x80x94(CH2)u(R2O)t(CH2)uY, and mixtures thereof. When R units comprise backbone branching units, R4 is preferably hydrogen of xe2x80x94(CH2)u(R2O)txe2x80x94(CH2)uY wherein the index t is greater than 0, preferably from 10 to 30; the index u is from 0 to 6; and Y is hydrogen, C1-C4 linear alkyl, xe2x80x94N(R1)2, an anionic unit, and mixtures thereof; preferably Y is hydrogen, or xe2x80x94N(R1)2. A preferred embodiment of backbone branching units comprises R4 equal to xe2x80x94(R2O)tH. The indices x, y, and z are each independently from 0 to 6.
vii) The formulator may suitably combine any of the above described R units to make a zwitterionic polyamine having a greater or lesser degree of hydrophilic character.
R1 units are the units which are attached to the backbone nitrogens. R1 units are selected from the group consisting of:
i) hydrogen; which is the unit typically present prior to any backbone modification.
ii) C1-C22 alkyl, preferably C1-C4 alkyl, more preferably methyl or ethyl, most preferably methyl. A preferred embodiment of the present invention in the instance wherein R1 units are attached to quaternary units (iv) or (v), R1 is the same unit as quaternizing unit Q. For example a J unit having the formula: 
iii) C7-C22 arylalkyl, preferably benzyl.
iv) xe2x80x94[CH2CH(OR4)CH2O]s(R2O)tY; wherein R2 and R4 are the same as defined herein above, preferably when R1 units comprise R2 units, R2 is preferably ethylene. The value of the index s is from 0 to 5. For the purposes of the present invention the index t is expressed as an average value, said average value from about 0.5 to about 100. The formulator may lightly alkyleneoxylate the backbone nitrogens in a manner wherein not every nitrogen atom comprises an R1 unit which is an alkyleneoxy unit thereby rendering the value of the index t less than 1.
v) Anionic units as described herein below.
vi) The formulator may suitably combine one or more of the above described R1 units when substituting the backbone of the zwitterionic polymers of the present invention.
Q is a quaternizing unit selected from the group consisting of C1-C4 linear alkyl, benzyl, and mixtures thereof, preferably methyl. As described herein above, preferably Q is the same as R1 when R1 comprises an alkyl unit. For each backbone N+ unit (quaternary nitrogen) there will be an anion to provide charge neutrality. The anionic groups of the present invention include both units which are covalently attached to the polymer, as well as, external anions which are present to achieve charge neutrality. Non-limiting examples of anions suitable for use include halogen, inter alia, chloride; methyl sulfate; hydrogen sulfate, and sulfate. The formulator will recognize by the herein described examples that the anion will typically be a unit which is part of the quaternizing reagent, inter alia, methyl chloride, dimethyl sulfate, benzyl bromide.
X is oxygen, xe2x80x94NR4xe2x80x94, and mixtures thereof, preferably oxygen.
Y is hydrogen, C1-C4 linear alkyl, xe2x80x94N(R1)2, or an anionic unit. Y is xe2x80x94N(R1)2 preferably when Y is part of an R unit which is a backbone branching unit. Anionic units are defined herein as xe2x80x9cunits or moieties which are capable of having a negative chargexe2x80x9d. For example, a carboxylic acid unit, xe2x80x94CO2H, is neutral, however upon de-protonation the unit becomes an anionic unit, xe2x80x94CO2xe2x88x92, the unit is therefore, xe2x80x9ccapable of having a negative charge. Non-limiting examples of anionic Y units include xe2x80x94(CH2)fCO2M, xe2x80x94C(O)(CH2)fCO2M, xe2x80x94(CH2)fPO3M, xe2x80x94(CH2)fOPO3M, xe2x80x94(CH2)fSO3M, xe2x80x94CH2(CHSO3M)xe2x80x94(CH2)fSO3M, xe2x80x94CH2(CHSO2M)(CH2)fSO3M, xe2x80x94C(O)CH2CH(SO3M)CO2M, xe2x80x94C(O)CH2CH(CO2M)NHCH(CO2M)CH2CO2M, xe2x80x94C(O)CH2CH(CO2M)NHCH2CO2M, xe2x80x94CH2CH(OZ)CH2O(R1O)tZ, xe2x80x94(CH2)fCH[O(R2O)tZ]xe2x80x94CHfO(R2O)tZ, and mixtures thereof, wherein Z is hydrogen or an anionic unit non-limiting examples of which include xe2x80x94(CH2)fCO2M, xe2x80x94C(O)(CH2)fCO2M, xe2x80x94(CH2)fPO3M, xe2x80x94(CH2)fOPO3M, xe2x80x94(CH2)fSO3M, xe2x80x94CH2(CHSO3M)xe2x80x94(CH2)fSO3M, xe2x80x94CH2(CHSO2M)(CH2)fSO3M, xe2x80x94C(O)CH2CH(SO3M)CO2M, xe2x80x94C(O)CH2CH(CO2M)NHCH(CO2M)CH2CO2M, and mixtures thereof, M is a cation which provides charge neutrality.
Y units may also be oligomeric or polymeric, for example, the anionic Y unit having the formula: 
xe2x80x83may be oligomerized or polymerized to form units having the general formula: 
wherein the index n represents a number greater than 1.
Further non-limiting examples of Y units which can be suitably oligomerized or polymerized include: 
As described herein above that a variety of factors, inter alia, the overall polymer structure, the nature of the formulation, the wash conditions, and the intended target cleaning benefit, all can influence the formulator""s optimal values for Qr, xcex94Q, and Q(+). For liquid laundry detergent compositions preferably less than about 90%, more preferably less than 75%, yet more preferably less than 50%, most preferably less than 40% of said Y units comprise an anionic moiety, inter alia, xe2x80x94SO3M comprising units. The number of Y units which comprise an anionic unit will vary from embodiment to embodiment. M is hydrogen, a water soluble cation, and mixtures thereof; the index f is from 0 to 6
The index n represents the number of backbone units wherein the number of amino units in the backbone is equal to n+1. For the purposes of the present invention the index n is from 1 to about 99. Branching units B are included in the total number of backbone units. For example, a backbone having the formula: 
has an index n equal to 4. The following is a non-limiting example of a polyamine backbone which is fully quaternized. 
The following is a non-limiting example of a zwitterionic polyamine according to the present invention. 
Preferred zwitterionic polymers of the present invention have the formula: 
wherein R units are C3-C6 alkylene units, preferably R is hexamethylene; R1 is hydrogen, Q, xe2x80x94(R2O)tY, and mixtures thereof, preferably xe2x80x94(R2O)tY; R2 is ethylene, Y is hydrogen, an anionic unit selected from the group consisting of xe2x80x94(CH2)fCO2M, xe2x80x94C(O)(CH2)fCO2M, xe2x80x94(CH2)fPO3M, xe2x80x94(CH2)fOPO3M, xe2x80x94(CH2)fOSO3M, xe2x80x94(CH2)fSO3M, xe2x80x94CH2(CHSO3M)(CH2)fSO3M, xe2x80x94CH2(CHSO2M)(CH2)fOSO3M, xe2x80x94CH2(CHSO2M)(CH2)fSO3M and mixtures thereof; preferably Y is hydrogen, xe2x80x94(CH2)fSO3M, and mixtures thereof. In a more preferred embodiment of the present invention at least 30% of Y units are anionic units having the formula xe2x80x94SO3M. M is hydrogen, a water soluble cation, and mixtures thereof; the index f is from 0 to about 10; Q is a quaternizing unit selected from the group consisting of C1-C4 linear alkyl, benzyl, and mixtures thereof; preferably Q is methyl or benzyl, more preferably methyl. X is a water soluble anion in sufficient quantity to provide electronic neutrality. The index m is from 0 to 20; preferably m is less than 10; more preferably m has the value of 0, 1, 2, and 3 providing polyamines having from 2 to 5 backbone nitrogen atoms. In one preferred embodiment m is 0 and R is hexamethylene which provides a backbone which is a hexamethylenediamine. Bis(hexamethylenediamine) backbones, wherein m is equal to 1, are also a preferred. The index t represents an average value for alkyleneoxy units and varies from 15 to 25. In one embodiment the formulator may not tightly ethoxylate and the number of EO units may range fully from 15 to 25, whereas in another equally useful embodiment the variability in the range of ethoxylation may be from 18.5 to 21.5. However, the formulator may select a means for ethoxylation which wherein each R1 unit comprises the same whole number of ethyleneoxy units.
Non-limiting examples of backbones according to the present invention include 1,9-diamino-3,7-dioxanonane; 1,10-diamino-3,8-dioxadecane; 1,12-diamino-3,10-dioxadodecane; 1,14-diamino-3,12-dioxatetradecane. However, backbones which comprise more than two nitrogens may comprise one or more repeating units having the formula:
H2Nxe2x80x94[Rxe2x80x94NH]xe2x80x94
for example a unit having the formula:
H2Nxe2x80x94[CH2CH2OCH2CH2NH]xe2x80x94
is described herein as 1,5-diamino-3-oxapentane. A backbone which comprises two 1,5-diamino-3-oxapentane units has the formula:
H2NCH2CH2OCH2CH2NHCH2CH2OCH2CH2NH2.
Further suitable repeating units include 1,8-diamino-3,6-diaxaoctane; 1,11-diamino-3,6,9-trioxaundecane; 1,5-diamino-1,4-dimethyl-3-oxaheptane; 1,8-diamino-1,4,7-trimethyl-3,6-dioxaoctane; 1,9-diamino-5-oxanonane; 1,14-diamino-5,10-dioxatetradecane.
The present invention affords the formulator with the ability to optimize the zwitterionic polymer for a particular use or embodiment. Not wishing to be limited by theory, it is believed that the backbone quaternization (positive charge carriers) interact with the hydrophobic soils, inter alia, clay, and the anionic capping units of the R1 units ameliorate the ability of surfactant molecules to interact, and therefore occupy, the cationic sites of the zwitterionic polymers. It is surprisingly found that the liquid laundry detergent compositions (HDL) which encompass the present invention are more effective in releasing hydrophilic soils when the backbones which comprise R units have a greater degree of alkylene unit character and which comprise an excess of backbone quaternary units with respect to the number of anionic units present.
The zwitterionic polymers of the present invention preferably comprise polyamine backbone which are derivatives of two types of backbone units:
i) normal oligomers which comprise R units of type (i), which are preferably polyamines having the formula:
H2Nxe2x80x94(CH2)x]n+1xe2x80x94[NHxe2x80x94(CH2)x]mxe2x80x94[NBxe2x80x94(CH2)x]nxe2x80x94NH2
wherein B is a continuation of the polyamine chain by branching, n is preferably 0, m is from 0 to 3, x is 2 to 8, preferably from 3 to 6; and
ii) hydrophilic oligomers which comprise R units of type (ii), which are preferably polyamines having the formula:
H2Nxe2x80x94[(CH2)xO]y(CH2)x]xe2x80x94[NHxe2x80x94[(CH2)xO]y(CH2)x]mxe2x80x94NH2
wherein m is from 0 to 3; each x is independently from 2 to 8, preferably from 2 to 6; y is preferably from 1 to 8.
Preferred backbone units are the units from (i). Further preferred embodiments are polyamines which comprise units from (i) which are combined with R units of types (iii), (iv), and (v), an non-limiting example of which includes the epihalohydrin condensate having the formula: 
As described herein before, the formulator may form zwitterionic polymers which have an excess of charge or an equivalent amount of charge type. An example of a preferred zwitterionic polyamine according to the present invention which has an excess of backbone quaternized units, has the formula: 
wherein R is a 1,5-hexamethylene, w is 2; R1 is xe2x80x94(R2O)tY, wherein R2 is ethylene, Y is hydrogen or xe2x80x94SO3M, Q is methyl, m is 1, t is 20. For zwitterionic polyamines of the present invention, it will be recognized by the formulator that not every R1 unit will have a xe2x80x94SO3 moiety capping said R1 unit. For the above example, the final zwitterionic polyamine mixture comprises at least about 40% Y units which are xe2x80x94SO3xe2x88x92 units.